title: Prenatal exposure to lead in Spain: cord blood levels and associated factors.
abstract: OBJECTIVE
  Lead is a known neurotoxic. Fetuses and infants are very vulnerable to lead exposure, since their blood-brain barrier is not completely formed. Hence, there is an importance for monitoring of blood lead levels prenatally and during early infancy. The aim of this study is to evaluate the prenatal exposure to lead and its association with maternal factors in four population based mother-child cohorts in Spain. The present research was carried out within the framework of the INMA project INfancia y Medio Ambiente (Environment and Childhood).
  
  
  METHODS
  A total of 1462 pregnant women were recruited between 2004 and 2008. Lead was analyzed in a sample of cord blood by thermal decomposition, amalgation, and Atomic Absorption Spectrometry. Maternal sociodemographic, lifestyle and dietary factors were obtained by questionnaires during pregnancy. A multivariate logistic regression model was constructed. The dependent variable was a dichotomous lead level variable (detected vs no detected, i.e. ≥ vs < 2μg/dL).
  
  
  RESULTS
  A low percentage of cord blood samples with lead levels ≥ 2μg/dL were found (5.9%). Geometric mean and maximum were 1.06μg/dL and 19μg/dL, respectively. Smoking at the beginning of pregnancy, age, social class, weight gain during pregnancy, gravidity, and place of residence were the maternal factors associated with detectable cord blood lead levels. Mother's diet does not appear to be a determining factor of lead exposure. Nevertheless, daily intake of iron and zinc may act as a protective factor against having cord blood lead levels ≥ 2μg/dL.
  
  
  CONCLUSIONS
  In the different regions of Spain taking part in this study, lead levels to which newborns are exposed are low. Mobilization of lead from bones may be the main contributor to the cord blood levels.
authors.affiliation: Centre of Public Health Research, Av Catalunya 21, 46020, Valencia, Spain. llop_sab@gva.es
authors.forename: Sabrina
authors.initials: S
authors.lastname: Llop
authors.forename: Xabier
authors.initials: X
authors.lastname: Aguinagalde
authors.forename: Jesus
authors.initials: J
authors.lastname: Vioque
authors.forename: Jesús
authors.initials: J
authors.lastname: Ibarluzea
authors.forename: Mònica
authors.initials: M
authors.lastname: Guxens
authors.forename: Maribel
authors.initials: M
authors.lastname: Casas
authors.forename: Mario
authors.initials: M
authors.lastname: Murcia
authors.forename: María
authors.initials: M
authors.lastname: Ruiz
authors.forename: Ascensión
authors.initials: A
authors.lastname: Amurrio
authors.forename: Marisa
authors.initials: M
authors.lastname: Rebagliato
authors.forename: Loreto Santa
authors.initials: LS
authors.lastname: Marina
authors.forename: Ana
authors.initials: A
authors.lastname: Fernandez-Somoano
authors.forename: Adonina
authors.initials: A
authors.lastname: Tardon
authors.forename: Ferran
authors.initials: F
authors.lastname: Ballester
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D007854:Lead / Q000097:blood*; D018811:Maternal Exposure / Q000706:statistics & numerical data*; D015999:Multivariate Analysis; D011247:Pregnancy; D012959:Socioeconomic Factors; D013030:Spain
chemical_list: D004785:Environmental Pollutants; D007854:Lead